'You want to know about the Clockwork Men?

'We work in their shadow, every tick and tock of our lives. We hear them in the workings of the Great Clock. We work hard, turn our hands — but we all wind down in time, and that is when they come for us: when our time is up.'

The TARDIS lands in between times, in a time where this is no time. A time in which nothing can possibly be. But something is...

The Doctor, Charley and C'rizz are rats in the wheelwork, a threat to the schedule of a world where timing is everything. And the seconds are counting down to a fateful future that has already happened. Unless they can beat the clock.

Tick, tock.